While temperature activation of CatSper was previously not known, scientists believed that the protein was activated by the pH level in the female reproductive channel. Temperature seemed like a primary factor, since mammalian evolution has developed numerous ways to help keep the male reproductive organs at or below the optimal 93.2 degrees Fahrenheit. Birds and other animals that lack these cooling adaptations for their male reproductive organs also do not have CatSper proteins on their sperm. Working like a ‘spermostat’In the new study, Lishko and her team used tiny micron-scaled tools and techniques originally made to study brain cells. While there have been some attempts to make male contraceptives that deactivate this calcium channel, those methods have not been very effective.